Rob, I had literally just hit send
when your note popped up.? Great minds?
73, John Payne W4CWZ
Rob
Bleumer wrote on 9/6/2023 7:04 AM:
toggle quoted message
Show quoted text
Hans,?
I
found on the QDX 12 V version a point where, on 40M and a certain
impedance of the antenna load the QDX started to oscilate at
transmitting. Current went up at oscilating from the normal arround
800mA to more than 1,2A. Thats why I am using a good buck converter
where I limit the current to max. 950mA and 11,8V. The antenna tuner is a
bridge QRP type, switching off the bridge after tuning.
Never fried a
BS170 until now. No other prptection.
Aboit the buck converter ther
was already a topic in this group.
Perhaps the oscilation is the real
problem.
